Add configuration for node announcement addresses

In certain node configurations a user might want or need to
announce different addresses to the network than the ones they
bind their tcp listeners to.

Author: aylagreystone

bindings/ldk_node.udl

@@ -7,6 +7,7 @@ dictionary Config {
 	string storage_dir_path;
 	Network network;
 	sequence<SocketAddress>? listening_addresses;
+	sequence<SocketAddress>? announcement_addresses;
 	NodeAlias? node_alias;
 	sequence<PublicKey> trusted_peers_0conf;
 	u64 probing_liquidity_limit_multiplier;
@@ -80,6 +81,8 @@ interface Builder {
 	[Throws=BuildError]
 	void set_listening_addresses(sequence<SocketAddress> listening_addresses);
 	[Throws=BuildError]
+	void set_announcement_addresses(sequence<SocketAddress> announcement_addresses);
+	[Throws=BuildError]
 	void set_node_alias(string node_alias);
 	[Throws=BuildError]
 	Node build();
@@ -108,6 +111,7 @@ interface Node {
 	void event_handled();
 	PublicKey node_id();
 	sequence<SocketAddress>? listening_addresses();
+	sequence<SocketAddress>? announcement_addresses();
 	NodeAlias? node_alias();
 	Bolt11Payment bolt11_payment();
 	Bolt12Payment bolt12_payment();
@@ -315,6 +319,7 @@ enum BuildError {
 	"InvalidSystemTime",
 	"InvalidChannelMonitor",
 	"InvalidListeningAddresses",
+	"InvalidAnnouncementAddresses",
 	"InvalidNodeAlias",
 	"ReadFailed",
 	"WriteFailed",

src/builder.rs

@@ -148,6 +148,8 @@ pub enum BuildError {
 	InvalidChannelMonitor,
 	/// The given listening addresses are invalid, e.g. too many were passed.
 	InvalidListeningAddresses,
+	/// The given announcement addresses are invalid, e.g. too many were passed.
+	InvalidAnnouncementAddresses,
 	/// The provided alias is invalid.
 	InvalidNodeAlias,
 	/// We failed to read data from the [`KVStore`].
@@ -184,6 +186,9 @@ impl fmt::Display for BuildError {
 				write!(f, "Failed to watch a deserialized ChannelMonitor")
 			},
 			Self::InvalidListeningAddresses => write!(f, "Given listening addresses are invalid."),
+			Self::InvalidAnnouncementAddresses => {
+				write!(f, "Given announcement addresses are invalid.")
+			},
 			Self::ReadFailed => write!(f, "Failed to read from store."),
 			Self::WriteFailed => write!(f, "Failed to write to store."),
 			Self::StoragePathAccessFailed => write!(f, "Failed to access the given storage path."),
@@ -413,6 +418,22 @@ impl NodeBuilder {
 		Ok(self)
 	}
 
+	/// Sets the IP address and TCP port which [`Node`] will announce to the gossip network that it accepts connections on.
+	///
+	/// **Note**: If unset, the [`listening_addresses`] will be used as the list of addresses to announce.
+	///
+	/// [`listening_addresses`]: NodeBuilder::set_listening_addresses
+	pub fn set_announcement_addresses(
+		&mut self, announcement_addresses: Vec<SocketAddress>,
+	) -> Result<&mut Self, BuildError> {
+		if announcement_addresses.len() > 100 {
+			return Err(BuildError::InvalidAnnouncementAddresses);
+		}
+
+		self.config.announcement_addresses = Some(announcement_addresses);
+		Ok(self)
+	}
+
 	/// Sets the node alias that will be used when broadcasting announcements to the gossip
 	/// network.
 	///
@@ -776,6 +797,17 @@ impl ArcedNodeBuilder {
 		self.inner.write().unwrap().set_listening_addresses(listening_addresses).map(|_| ())
 	}
 
+	/// Sets the IP address and TCP port which [`Node`] will announce to the gossip network that it accepts connections on.
+	///
+	/// **Note**: If unset, the [`listening_addresses`] will be used as the list of addresses to announce.
+	///
+	/// [`listening_addresses`]: NodeBuilder::set_listening_addresses
+	pub fn set_announcement_addresses(
+		&self, announcement_addresses: Vec<SocketAddress>,
+	) -> Result<(), BuildError> {
+		self.inner.write().unwrap().set_announcement_addresses(announcement_addresses).map(|_| ())
+	}
+
 	/// Sets the node alias that will be used when broadcasting announcements to the gossip
 	/// network.
 	///

src/config.rs

@@ -117,6 +117,10 @@ pub struct Config {
 	/// **Note**: We will only allow opening and accepting public channels if the `node_alias` and the
 	/// `listening_addresses` are set.
 	pub listening_addresses: Option<Vec<SocketAddress>>,
+	/// The addresses which the node will announce to the gossip network that it accepts connections on.
+	///
+	/// **Note**: If unset, the `listening_addresses` will be used as the list of addresses to announce.
+	pub announcement_addresses: Option<Vec<SocketAddress>>,
 	/// The node alias that will be used when broadcasting announcements to the gossip network.
 	///
 	/// The provided alias must be a valid UTF-8 string and no longer than 32 bytes in total.
@@ -168,6 +172,7 @@ impl Default for Config {
 			storage_dir_path: DEFAULT_STORAGE_DIR_PATH.to_string(),
 			network: DEFAULT_NETWORK,
 			listening_addresses: None,
+			announcement_addresses: None,
 			trusted_peers_0conf: Vec::new(),
 			probing_liquidity_limit_multiplier: DEFAULT_PROBING_LIQUIDITY_LIMIT_MULTIPLIER,
 			anchor_channels_config: Some(AnchorChannelsConfig::default()),
@@ -457,6 +462,12 @@ mod tests {
 		node_config.node_alias = Some(alias_frm_str("LDK_Node"));
 		assert!(!may_announce_channel(&node_config));
 
+		// Set announcement addresses with listening addresses unset
+		let announcement_address = SocketAddress::from_str("123.45.67.89:9735")
+			.expect("Socket address conversion failed.");
+		node_config.announcement_addresses = Some(vec![announcement_address]);
+		assert!(!may_announce_channel(&node_config));
+
 		// Set node alias with an empty list of listening addresses
 		node_config.listening_addresses = Some(vec![]);
 		assert!(!may_announce_channel(&node_config));

src/lib.rs

@@ -457,8 +457,10 @@ impl Node {
 								continue;
 							}
 
-							let addresses = if let Some(addresses) = bcast_config.listening_addresses.clone() {
-								addresses
+							let addresses = if let Some(announcement_addresses) = bcast_config.announcement_addresses.clone() {
+								announcement_addresses
+							} else if let Some(listening_addresses) = bcast_config.listening_addresses.clone() {
+								listening_addresses
 							} else {
 								debug_assert!(false, "We checked whether the node may announce, so listening addresses should always be set");
 								continue;
@@ -802,6 +804,14 @@ impl Node {
 		self.config.listening_addresses.clone()
 	}
 
+	/// Returns the addresses that the node will announce to the network.
+	pub fn announcement_addresses(&self) -> Option<Vec<SocketAddress>> {
+		self.config
+			.announcement_addresses
+			.clone()
+			.or_else(|| self.config.listening_addresses.clone())
+	}
+
 	/// Returns our node alias.
 	pub fn node_alias(&self) -> Option<NodeAlias> {
 		self.config.node_alias